This invention relates to a vapor recovery apparatus and method and, more particularly to such an apparatus and method for recovering gasoline vapors from a gasoline dispensing systems.
In a gasoline service station for dispensing gasoline to vehicles, several gasoline dispensing units, or pumps, are provided which receive gasoline stored in one or more underground storage tanks and dispense the gasoline, via dispensing nozzles, to the vehicles.
In these arrangements, gasoline vapor is present in the fuel tank of the vehicle and released from the gasoline flow which can discharge to atmosphere if not properly recovered. In compliance with government regulations that require this gasoline vapor to be recovered, various types of systems have evolved.
By far the most common recovery systems of this type utilize a dual hose arrangement with one hose supplying the gasoline from the underground storage tank to the dispensing nozzle for dispensing into the vehicle, and the other hose passing the gasoline vapors from the vehicle tank to the underground storage tank. With all currently known vapor recovery systems of this type, extensive vapor return piping, along with associated pumps and valves, are required to conduct the collected vapor from the vehicle tank, through the dispensing unit and back to the underground storage tank. Of course, in relatively old installations, if this piping has not been provided during the initial construction, the station forecourt has to be dug up to install the underground portion of the system, which considerably adds to the cost of the installations.
Therefore what is needed is a vapor recovery system that eliminates the need to transfer the recovered vapors to the underground gasoline storage tank, and therefore eliminates the cost and complexity of such systems.
The present invention is directed to an apparatus and method for recovering vapor during the dispensing of fuel via a hose into a vehicle tank. An embodiment of the invention has a compressor disposed in a vapor passage. The compressor is activated in response to the dispensing of the fuel for drawing the vapor from the tank and into the vapor passage. Blades on the compressor separate the air from the gasoline vapor. The recovered vapor is reintroduced into the fuel flow and the air is released to the atmosphere.
An advantage of the invention is that it operates by motion of the fluid flow to the vehicle tank, and therefore saves on electrical power cost because no electrical power is needed.
An advantage of the invention is that recovered vapor can be reintroduced back into the fuel stream at the fuel hose, thereby eliminating a lengthy fluid path back to the source fuel tank. This reduces the susceptibility of the system to leaks, for example in the dispenser itself, in the underground pipes, or at the fuel tank or tank vent. Also, because the recovered vapor is not routed to the fuel tank, it does not pressurize the fuel tank.